Buddy
/bʌd.i/
noun
A friend or casual acquaintance.
“They have been buddies since they were in school.”
A partner for a particular activity.
“drinking buddies”
An informal and friendly address to a stranger; a friendly (or occasionally antagonistic) placeholder name for a person one does not know.
“Hey, buddy, I think you dropped this.”
verb
To assign a buddy, or partner, to.